NEED Help ! 2009 GS500

[gsvaught]

Hey I need help with my gs500. after riding about 15-30 min, I came to a stop light and then all of a sudden the rpm went to though the roof around 6000. after seeing this I shut it off. Then I started back up and it did it again. I check the choke and it was off, and I push back the throttle all the way and it still going to 6000 rpm. Then after waiting 5 min I tried to start it again and it would idle really low then shoot back up to 6000 rpm. some how I got the rpm to stay around 1300 rpm for a second so I could get home. does anybody have a clue what happen? I have look around on this forum and I think it maybe a vacuum leak?     

[Watcher]

Vacuum leak wouldn't cause a 6000 rpm spike.  Vacuum leaks are typically responsible for high and erratic idles and poor throttle response and such by leaning out the fuel/air mixture.
To get the RPMs that high you have to be picking up fuel, and a vacuum leak isn't going to do that.

That sounds like a stuck throttle, or maybe a jammed carb slide.
Rolling back the hand grip won't do much if the throttle butterfly itself is stuck open.
I can't remember if you can reach this or not from "outside" the carbs to check it.  Someone else will chime in.

Could also be the result of the idle screw being set too high.  Sometimes you can't tell if this is set right or not until the choke comes off and the engine is nice and hot.  20 minutes or so sounds about right.
Have you recently modified anything?
New air-filter?  Rejet?  Exhaust?

[gsvaught]

No its all stock, just took her for a ride down the road and everything seemed fine. but I'm going to do another longer ride tomorrow and see if it does it again. if it still happen should I clean the carb and lube up that Butterfly valve? 

[Big Rich]

Check each component of the throttle system - from the grip / throttle tube, cable itself, cable routing, butterfly valve, etc. And if it happens again (in neutral I want to add) try blipping the throttle and see if it'll slam shut. It might rev up to 10k so be prepared to kill it.

A sticky slide is easy to check - with the air box off, you can push the slide up with your finger and let it drop. Do that a few times until your confident it's not the problem.